**Core Concept**
The World Health Organization (WHO) International Classification of Functioning, Disability and Health (ICF) framework is a crucial concept in understanding the relationship between health conditions and their impact on an individual's functioning. This framework distinguishes between three key concepts: impairment, disability, and handicap. Impairment refers to any loss or abnormality of psychological, physiological, or anatomical structure or function. Disability is a restriction or lack of ability (resulting from an impairment) to perform an action in the manner or within the range considered normal for a human being. Handicap is a disadvantage for a given individual, resulting from an impairment or a disability, that limits or prevents the fulfillment of a role that is normal (depending on age, sex, social, and cultural factors) for that individual.

**Why the Correct Answer is Right**
The correct answer, Disability, refers to the lack of ability of an individual to perform routine activities due to a restriction or lack of ability resulting from an impairment. For example, a person with a spinal cord injury may experience weakness or paralysis in their limbs, leading to a disability in performing daily activities such as walking or dressing. In this case, the impairment (spinal cord injury) leads to a disability (inability to perform daily activities).

**Why Each Wrong Option is Incorrect**
**Option A:** Disease is a broad term that refers to any condition that impairs normal functioning of the body. While disease can lead to impairment and disability, it is not the correct answer in this context.
**Option B:** Impairment is a loss or abnormality of psychological, physiological, or anatomical structure or function, but it does not necessarily lead to a lack of ability to perform routine activities.
**Option D:** Handicap is a disadvantage for a given individual resulting from an impairment or a disability, but it is not the same as a lack of ability to perform routine activities.

**Clinical Pearl / High-Yield Fact**
It is essential to remember that the ICF framework distinguishes between impairment, disability, and handicap, and that disability refers specifically to the lack of ability to perform routine activities due to a restriction or lack of ability resulting from an impairment.

**✓ Correct Answer: C. Disability**